Robbins police say a man fatally shot his wife and children in front of his stepson and his wife's grandson. Police later found his body in the back of the home.

Two other children in the house were able to escape from the killer. The shooting started late Sunday night at a home in south suburban Robbins.

Police are calling this a horrific crime without any apparent reason. The home where the murders happened has been boarded up but is still considered a crime scene. Police say these are the first murders to take place in Robbins in the last two years.

How do you make sense of the unthinkable? That's what one Robbins family is trying to do Monday as they mourn the loss of four of their own.

"They can do all the investigations they want but I can tell you this, he was not a monster. I don't know what went wrong. I don't I really don't," said Toni Gardner, shooter's cousin.

Police say that it was just after 10:30 Sunday night when 43-year old Michael Worsham walked into his Robbins home at 136th and Pulaski and started shooting. First, it was his 15-year old son Steven, then his wife, 42-year old Michelle Ollie, and finally his 17-year old daughter Trisha, shot on the front porch as she tried to escape the home with her 14-year-old brother and five-year -old nephew. The last two were the only ones to escape alive. Michael Worsham was later found dead inside the home, but without any apparent wounds.

"The 14-year old also attempted to disarm the gun from his stepfather. Stepfather told him if he stopped trying to disarm him he would let him live," said Chief Mitchell Davis, Robbins Police Department.

Police can find no motive for the shooting. They say Michael Worsham, who was a security guard at Thornton Township High School, had no criminal history. And there were no prior domestic incidents at the address. His wife, Michelle Ollie, worked as a child care worker at an emergency shelter for girls just across the street. Her boss said nothing appeared out of the ordinary.

"She was a loving wife, a loving mother and a loving grandmother," said Denice Gathings, co-worker.

Meanwhile, grief counselors were on hand at Shepard High School in Palos Heights, where both teenagers were students.

"They were great kids, caring kids and it's a reflection of how the students reacted today. They are very saddened by their loss. Very well-liked, popular kids and very caring," said Dr. Josh Barron, principal, Shepard High School.

Police say it might be a day or two before they have an official cause of death for Michael Worsham. There is some speculation by investigators that he may have had a heart attack after the shootings.

On Monday evening, a large group of people from the neighborhood -- mostly teenagers -- held a candlelight vigil outside the home where the murders occurred.